1. Field of the Invention
The present invention relates to an actor node, a sensor node, a coverage block change method, a parameter change method, a program, and an information processing system.
2. Description of the Related Art
Wireless sensor network (WSN) has been studied for a long time. The wireless sensor network is a system for obtaining data from many sensor nodes arranged within a predetermined region and performing a predetermined processing based on the obtained data. Recently, a method using an actor node capable of moving in a network field has been used in order to easily obtain data from many sensor nodes. Such system using the actor node to collect data is called a wireless sensor and actor network (WSAN).
This WSAN is a system used to achieve an object such as monitoring whether there is an intruder and preventing fire. When an event occurs that may cause failure of an object to be achieved, such as presence of an intruder and an occurrence of fire, the system performs operation to get rid of this event.
In the WSAN, various kinds of information and instructions are transmitted in communication between an actor node and a sensor node and among actor nodes. Accordingly, it is important to improve the security of communication between the nodes. Therefore, studies have been performed for the purpose of improving the security of communication in the WSAN (for example, see X. Cao, M. Huang, Y. Chen and G. Chen, “Hybrid Authentication and Key Management Scheme for WSANs”, ISPA Workshop 2005, LNCS 3759, pp. 454-465, 2005, and B. Yu, J. Ma, Z. Wang, D. Mao and C. Gao, “Key Establishment Between Heterogenous Nodes in Wireless Sensor and Actor Networks”, IWSN 2006, LNCS 3842, pp. 196-205, 2006.).